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What is a Computer?
A computer is an electronic device that accepts data from the user, processes it, produces results, displays them to the users, and stores the results for future usage. Data is a collection of unorganized facts & figures and does not provide any further information regarding patterns, context, etc. Hence data means "unstructured facts and figures". Information is a structured data i.e. organized meaningful and processed data. To process the data and convert into information, a computer is used. HISTORY OF COMPUTERS The history of computer begins with the birth of abacus which is believed to be the first computer. It is said that Chinese invented Abacus around 4, years ago. It was a wooden rack which has metal rods with beads mounted on them. The beads were moved by the abacus operator according to some rules to perform arithmetic calculations. Abacus is still used in some countries like China, Russia and Japan. An image of this tool is shown below; Napier's Bones It was a manually-operated calculating device which was invented by John Napier (1550-1617) of Merchiston. In this calculating tool, he used 9 different ivory strips or bones marked with numbers to multiply and divide. So, the tool became known as "Napier's Bones. It was also the first machine to use the decimal point. Pascaline
Pascaline is also known as Arithmetic Machine or Adding Machine. It was invented between 1642 and 1644 by a French mathematician-philosopher Biaise Pascal. It is believed that it was the first mechanical and automatic calculator. Difference Engine In the early 1820s, it was designed by Charles Babbage who is known as "Father of Modern Computer". It was a mechanical computer which could perform simple calculations. It was a steam driven calculating machine designed to solve tables of numbers like logarithm tables. Analytical Engine This calculating machine was also developed by Charles Babbage in 1830. It was a mechanical computer that used punch-cards as input. It was capable of solving any mathematical problem and storing information as a permanent memory.
Speed
A computer works with much higher speed and accuracy compared to humans while performing mathematical calculations. Computers can process millions (1,000,000) of instructions per second. The time taken by computers for their operations is microseconds and nanoseconds.
Accuracy
Computers perform calculations with 100% accuracy. Errors may occur due to data inconsistency or inaccuracy.
Diligence
A computer can perform millions of tasks or calculations with the same consistency and accuracy. It doesn’t feel any fatigue or lack of concentration. Its memory also makes it superior to that of human beings.
Versatility
Versatility refers to the capability of a computer to perform different kinds of works with same accuracy and efficiency.
Reliability
A computer is reliable as it gives consistent result for similar set of data i.e., if we give same set of input any number of times, we will get the same result. Automation Computer performs all the tasks automatically i.e. it performs tasks without manual intervention.
Memory
A computer has built-in memory called primary memory where it stores data. Secondary storage are removable devices such as CDs, pen drives, etc., which are also used to store data HARDWARE/ANATONMY OF COMPUTER
Computer hardware includes the physical parts of a
computer, such as a case, central processing unit (CPU), random
access memory (RAM), monitor, and mouse which processes the
input according to the set of instructions provided to it by the user
and gives the desired output.
The computer has mainly has two major components:
1. Hardware
2. Software
B. B. Control Unit: The Control unit coordinates and controls the
data flow in and out of the CPU, and also controls all the
operations of ALU, memory registers and also input/output units.
It is also responsible for carrying out all the instructions stored in
the program.
C. Memory Registers: A register is a temporary unit of memory
in the CPU. These are used to store the data, which is directly
used by the processor. Registers can be of different sizes(16 bit,
32 bit, 64 bit and so on) and each register inside the CPU has a
specific function, like storing data, storing an instruction, storing
address of a location in memory etc
. Output Unit :
The output unit consists of output devices that are attached to the
computer. It converts the binary data coming from the CPU to
human understandable form. The common output devices are
monitor, printer, plotter, etc.
INPUT DEVICES
The devices which are used to give input to the computer system are known as input devices. some of the important input devices Keyboard Mouse Joy Stick Light pen Track Ball Scanner Graphic Tablet Microphone Magnetic Ink Card Reader(MICR) Optical Character Reader(OCR) Bar Code Reader Optical Mark Reader(OMR)
Keyboard
Keyboard is the most common and very popular input device which helps to input data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions.
Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for Windows and Internet. QWERTY keyboards are commonly found in personal computers and are considered standard on typewriters. Mechanical Keyboards Typists and gamers who demand accurate and enjoyable typing love these switches because they give tactile and aural feedback. Ergonomic Keyboards Typing for long periods can cause muscle strain and discomfort; ergonomic keyboards are specifically designed to alleviate these issues. These include split keyboards and contoured keyboards, which are curved to fit the natural hand posture. Virtual Keyboards Software-based virtual keyboards are utilised on smartphones and tablets. Tap or swipe virtual keys to enter text or directions. Foldable Keyboards Travellers and people who require a small keyboard may fold or wrap them up for storage and transport.
Light Pen
Light pen is a pointing device similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a small tube.
Scanner
Scanner is an input device, which works more like a photocopy machine. Scanner captures images from the source which are then converted into a digital form that can be stored on the disk. These images can be edited before they are printed.
Digitizer
Digitizer is an input device which converts analog information into digital form. Digitizer can convert a signal from the television or camera into a series of numbers that could be stored in a computer.
Microphone
Microphone is an input device to input sound that is then stored in a digital form.
Bar Code Readers
Bar Code Reader is a device used for reading bar coded data (data in the form of light and dark lines). Bar Code Reader scans a bar code image, converts it into an alphanumeric value, which is then fed to the computer that the bar code reader is connected to.
Optical Mark Reader (OMR)
Graphic Plotter
A plotter, which is a type of printer, receives instructions from a computer to produce line drawings on paper using one or more automated pens
Printers
A printer is an output device, which is used to print processed data on paper. It is one of the most popular output devices.
Speakers
Speakers are standard output devices that are used to hear sound clearly from a measurable distance.
Projector
A projector is an output device powered by light is known as a projector. It effectively displays processed results generated by a computer device and is used to showcase images on a projection screen.
Types of Computer
We can categorize computer in two ways: on the basis of data handling capabilities and size. On the basis of data handling capabilities , the computer is of three types:
nuclear energy research. The first supercomputer was developed by Roger Cray in 1976.
Characteristics or applications of supercomputers:
o It produces excellent results in animations. o It is used for virtual testing of nuclear weapons and critical medical tests. o It has the ability to decrypt your password to enhance protection for security reasons.
Applications of mainframe computers:
o It helps in the diagnosis of various critical diseases and in producing accurate results in brain injuries, strokes, etc. o It also used in a smog control system where it predicts the level of fog and other pollutants in the atmosphere. 2) Mainframe computer Mainframe computers are designed to support hundreds or thousands of users simultaneously. They can support multiple programs at the same time.
Characteristics of Mainframe Computers:
o It has a very long life. It can run smoothly for up to 50 years after proper installation. o It has the ability to share or distribute its workload among other processors and input/output terminals. o It has the ability to protect the stored data and other ongoing exchange of information and data.
Applications of mainframe computers:
o In health care, it enabled hospitals to maintain a record of their millions of patients in order to contact them for treatment or related to their appointment, medicine updates or disease updates.
o In the field of education , it helps big universities to store, manage and retrieve data related to their courses, admissions, students, teachers, employees and affiliated schools and colleges. Miniframe or Minicomputer It is a midsize multiprocessing computer. It consists of two or more processors and can support 4 to 200 users at one time. Miniframe computers are used in institutes and departments for tasks such as billing, accounting and inventory management. A minicomputer lies between the mainframe and microcomputer as it is smaller than mainframe but larger than a microcomputer.
Characteristics of miniframe or minicomputer:
o It is light weight that makes it easy to carry and fit anywhere. o It is less expensive than mainframe computers. o It is very fast compared to its size. o It remains charged for a long time.
Applications of minicomputers:
o Data management : It is an excellent device for small organizations to collect, store and share data. Local hospitals and hotels can use it to maintain the records of their patients and customers respectively. o Communications Portal : It can also play the role of a communication device in larger systems by serving as a portal between a human operator and a central processor or computer. 4) Workstation Workstation is a single user computer that is designed for technical or scientific applications. It has a faster microprocessor, a large amount of RAM and high speed graphic adapters. It generally performs a specific job with great expertise ; accordingly, they are of different types such as graphics workstation, music workstation and engineering design workstation.
Characteristics of workstation computer:
o It is a high-performance computer system designed for a single user for business or professional use. o It has larger storage capacity, better graphics, and more powerful CPU than a personal computer.
words, the software is a computer program that provides a set of
instructions to execute a user’s commands and tell the computer
what to do. For example like MS-Word, MS-Excel, PowerPoint, etc.
" Software is a set of programs (sequence of instructions) that allows the users to perform a well-defined function or some specified task. "
Types of Software
oftware's are broadly classified into two types, i.e., System Software and Application Software.
Difference Between System Software and
Application Software
System Software Application Software
It is designed to manage the
resources of the computer system,
like memory and process
It is designed to fulfill the
requirements of the user for
performing specific tasks.
System Software Application Software
management, etc.
Written in a low-level language.
Written in a high-level
language.
Less interactive for the users. More interactive for the users.
System software plays vital role for
the effective functioning of a
system.
Application software is not so
important for the functioning of
the system, as it is task specific.
It is independent of the application
software to run.
It needs system software to run.
System Software
System software is software that directly operates the computer
hardware and provides the basic functionality to the users as well
as to the other software to operate smoothly
It is like an interface between hardware and user applications, it
helps them to communicate with each other because hardware
understands machine language(i.e. 1 or 0)
so system software converts the human-readable language into
machine language and vice versa.
System Software:
Operating System
Device Drive
Utility Software
Operating System: It is the main program of a computer
system. When the computer system ON it is the first software that
loads into the computer’s memory. Basically, it manages all the
resources such as computer memory, CPU, printer, hard disk, etc.,
and provides an interface to the user.
o operating systems are Microsoft Windows, Apple's iOS, Android, CentOS, Linus Utility Utility software is developed to provide support in analyzing, optimizing, along configuring and maintaining a computer.
